A line of voters stretches down the street as they wait for a polling site to open in New York, Tuesday, Nov. 8, 2016. (AP Photo/David Goldman)

WASHINGTON (MEDIA GENERAL) — Election Day is finally here and the stakes could not be higher, from the top of the ballot to the bottom.

Thousands of candidates are running in races ranging from president to city council.

After 500-plus days of news coverage, hundreds of opinion polls and zillions (a rough approximation) of think pieces on the state of American politics, here are the states and races that political insiders will be watching the closest Tuesday night.

White House: Clinton stands firm

Hillary Clinton’s team is confident that Democratic nominee will end the day as president-elect.

The final round of national polls (ABC, CBS, NBC) all leaned in Clinton’s favor by a few points, giving the former secretary of state a slight edge over Republican nominee Donald Trump.

Clinton also edged out Trump in the final tallies issued by sites like FiveThirtyEight and NYT’s Upshot, which use algorithms and weighted measures to predict the final outcome.

We’ve come a long way since the days of “Dewey defeats Truman,” but polls have been all over the place this cycle, so turnout in battleground states will be key.

Here are the biggies, east to west: Florida, North Carolina, New Hampshire, Pennsylvania, Ohio, Michigan, Wisconsin, Colorado, Nevada.

Trump certainly still has an opportunity, narrow as it may be, to change the game by bagging crucial swing states.

He spent his final night on the trail revving up huge crowds in New Hampshire and Michigan, which he sees as ripe for the picking.

If Republicans can poach Florida, North Carolina, Pennsylvania and New Hampshire from the ”D” column, the race could be called late into the night as news organizations await specific numbers from western states.

If not, we could have a winner by midnight.

The winner needs 270 electoral votes (of 538) to win.

Senate: A coin flip

A total of 34 Senate races are being waged this year, with Republicans defending 24 of those seats.

Senators win six-year terms, so many of the vulnerable GOPers vying to retain their seats this year are the same ones swept to victory during the anti-establishment Tea Party flood of 2010.

As Senate Republicans have learned, midterms are a different animal than presidential cycles where the top of the ticket can more directly help or hurt their chances of winning.

The Senate is currently comprised of 54 Republicans, 44 Democrats and two Independents who caucus with Democrats.

It looked to be a promising year for Democrats, who need to pick up at least four additional seats to pull even with Republicans.

Some Democrats’ relatively good fortunes fizzled over the past few weeks following the FBI Director James Comey’s letter — which turned out to be a false alarm — regarding the further inspection of emails which passed through Clinton’s private email server during her time in President Obama’s cabinet.

A handful of the swing races are neck and neck, according to poll averages tabulated by Real Clear Politics, and could go down to the wire.

If either party captures 51 seats, they will claim the majority for the next two years, including control of the Senate legislative calendar and powerful committee chairmanships.

Depending on the outcome of the presidential race, a one-vote majority could become a boost or giant headache for the next president.

Should Democrats pick up four seats and tie the Senate 50-50, the incoming vice president would declare his party the new majority.

A power-sharing deal would be on the table, as was last implemented during an evenly split Senate in 2000, but such a compromise would not be a foregone conclusion in this pitched political atmosphere.

House: Republicans look strong

The U.S. House of Representatives has 435 members.

There are currently 246 Republicans and 186 Democrats serving in the House, plus three vacant seats.

Unlike senators who represent entire states, House members represent districts within states that are often carved up by state legislatures to naturally align with a single party.

Urban districts lean left while rural areas favor the GOP.

Precinct volunteer Roy Reese puts up signs outside of precinct 39 at the First Church of the Open Bible, Tuesday, Nov. 8, 2016, in Des Moines, Iowa. (AP Photo/Charlie Neibergall)

Gerrymandering, the practice of dissecting states into politically advantageous parcels, ensures that each party has secure seats that are never in danger.

This eliminates much of the suspense that’s associated with presidential and Senate races, since a rural Nebraska district is unlikely to see a surge of Latino voters, motivated by Trump’s rhetoric, swing the entire contest.

Likewise, a hidden majority of Republicans don’t usually descend on urban polling booths to launch conservative underdogs to victory.

Given the safety of most House members, analysts have projected a modest gain in seats for Democrats in swing districts, but predict the House will remain firmly under Republican control.

The big question mark is whether current Speaker Paul Ryan, R-Wisc., will retain his speakership or face a coup by ultra-conservative members who resent his moderate immigration policies and tepid support of Donald Trump.